Kentucky St. and Cornwall Ave. Rain Garden
Kentucky St. and Cornwall Ave. Rain Garden
Kentucky St. and Cornwall Ave. Rain Garden
Where is this located? It’s at the corner of Kentucky Street and Cornwall Avenue next to Assumption Church.
What’s special about this place? Runoff flows into the first bay capturing sediment for easy clean out by maintenance crews. Runoff flows over the rocks called energy dissipators. Then it enters the rain garden planted with reeds and sedges that soak up the runoff. The concrete curbs keep the stormwater from flowing out onto the street. The rain garden connects to under-drains which take the treated stormwater away and eventually to the bay.
About Rain Gardens
A rain garden is a bowl-shaped garden that collects, absorbs, and filters the rainwater that runs off hard surfaces including parking lots, driveways, sidewalks, lawns, and roofs. They provide on-site cleaning of stormwater by using special soil mixtures and low-maintenance plants that soak up runoff. The soil mixes used in rain gardens are selected to allow water to soak in rapidly, treat runoff, and support plant growth. Hardy, often native, plants are carefully selected for each site, including wildflowers, grasses, rushes, ferns, shrubs, and even small trees. These plants can have the added benefit of attracting pollinators, providing habitat for beneficial insects and birds, adding beauty, and improving neighboring property values.
Rain gardens can be small and home-made, or they can be engineered with specific materials to be highly effective. Home-made rain gardens are usually applied in smaller, residential systems working to intercept runoff that would otherwise flow onto streets. Engineered rain gardens are a type of bioretention basin and are sized for specific water quality treatment and flow control capacity that includes designed soil mixes and, often, under-drains and control structures. All the rain gardens highlighted on these tours are engineered bioretention facilities.
Water Quality Benefit: Rain gardens can capture sediment and bacteria, capture oil, pesticides, and fertilizers, and use their mulch layer to bind-up dissolved metals. Plant roots also are host to diverse microbial and fungal populations that filter pollution using biological processes.
Water Quantity Benefit: Special soil mixtures are chosen to allow water to soak into the ground. Roots break up the soil so water can soak into the ground more easily. By absorbing runoff from hard surfaces, rain gardens reduce flooding on neighboring property, reduce erosion in streams, and may recharge local groundwater.

Drains almost 1/4 acre.
Where does this stormwater runoff come from? The stormwater at this site comes from the half of Kentucky Street next to the rain garden.
Where does this stormwater runoff flow next? Stormwater that does not infiltrate at this site flows through large pipes under Cornwall Avenue to an outfall above Whatcom Creek under the bridge.
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Curbs enclose engineered rain gardens filled with soil, special mulch, and plants. Underneath, a drain pipe directs treated stormwater through large pipes under Cornwall Avenue to an outfall above Whatcom Creek under the bridge.
The metal grate prevents leaves and larger debris from entering the stormwater system below. A pipe directs treated stormwater under Cornwall Avenue to an outfall above Whatcom Creek under the bridge.
The space used for the rain garden here and in other places around downtown did not take away parking spots. The installation also included sidewalk bumpouts to improve pedestrian safety.
The bumpouts associated with these rain gardens makes the crosswalk shorter, safer, and improved access for people with strollers, walkers, canes, or wheelchairs.
This rain garden is engineered to store and treat stormwater. Runoff flows out through the under-drain under Cornwall Avenue to an outfall above Whatcom Creek under the bridge.
Stormwater comes from church side of Kentucky Street. The treated runoff flows down pipes under Cornwall Avenue to Whatcom Creek.